The LS-100 grating spectroradiometer is specially designed for measuring the spectral irradiance of solar simulators which are used in solar cells ressearch. The LS-100 is calibrated against a NIST-traceable standard lamp. It is compact and very easy to operate. The LS-100 is controlled by a PC via a RS232C cable, so that data can be automatically obtained using the operating software. The measurement/analysis software offers advances functionalities to process the obtained data.